If you are weighing a private-island home as an investment, Sunset Key deserves a closer look. The island’s rarity, resort integration and easy access to Old Town Key West create a distinct income profile that blends lifestyle with yield. In this guide, you’ll see how constrained supply, seasonality, on-island services and local rules shape returns, plus the due diligence steps that protect your downside. Let’s dive in.

Why Sunset Key stands out

Sunset Key is a small, privately held island just off Key West. It pairs a limited collection of private residences with a boutique resort experience presented through the operator’s platform. According to the property’s marketing, inventory is typically described as about 40 stand-alone cottages with additional private homes, which keeps overall supply extremely scarce and helps support premium pricing and long-term values. You can review the integrated resort and residences overview on the operator’s site for context on product mix and amenities at Sunset Key Cottages and Residences.

Access is part of the value story. Guests and owners reach the island by scheduled launch from the sister marina at Opal Key in downtown Key West, with services coordinated across reservations, concierge and food and beverage. That tight link to the mainland experience allows for hotel-style packaging, group stays and special events that a typical stand-alone short-term rental may not capture as consistently.

Demand and seasonality in Monroe County

Key West and the Lower Keys see pronounced seasonal swings. The traditional high season runs from late fall through spring, with peak winter months delivering the strongest ADRs and occupancy. Shoulder periods in spring and fall remain attractive for well-marketed, higher-end stays, while summer tends to soften and overlaps with hurricane season. Destination updates for the Florida Keys note continued enhancements to air access and meetings demand, which support higher-yield travel segments. See the Keys’ meetings and travel context in this Florida Keys destination brief.

What this means for your model:

• Winter is your revenue engine. Underwrite materially higher ADR and occupancy from December through March.
• Shoulders can perform. Target events, reunions and corporate groups in April–May and October–November.
• Summer requires a plan. Expect more monthly rentals, longer stays or strategic discounting, and model a hurricane reserve.

Nightly vs. monthly: choosing your income path

Before assuming nightly revenue, confirm what is legal for the specific parcel. Monroe County defines a Special Vacation Rental as a dwelling rented for less than 28 days. Many residential districts do not allow nightly stays, and where they are permitted you need an annual special vacation rental permit, a licensed manager and Fire & Life Safety inspections. Review definitions, fees and compliance steps on the county’s Special Vacation Rental Program page.

If nightly rentals are not permitted, or if you prefer stability, a monthly strategy can still produce attractive, seasonal cash flow in the Keys. If nightly is permitted and you participate in a resort program, your gross revenue potential may rise with hotel-grade services and distribution, but operating costs and commissions will be higher.

Industry benchmarks for full-service management fees typically range from about 15 to 30 percent of gross bookings for third-party vacation rental managers. On-site resort rental programs that include reservations, housekeeping, concierge, launch coordination and marketing commonly retain about 25 to 40 percent. Use these ranges as context while you confirm exact terms in the operator’s agreement. See fee norms summarized here: average vacation rental management fees.

How resort integration can lift yield

Resort integration changes both demand capture and guest expectations on Sunset Key. With shared reservations, concierge and a dedicated ferry, the operator can package accommodations with on-island dining and experiences, increasing willingness to pay for multi-bedroom cottages and group blocks. That mix supports premium ADRs relative to independent homes, especially for weddings, incentive trips and family reunions.

It also raises the service bar. Linen rotations, optional daily housekeeping, 24-hour guest contact, pool and beach operations and F&B coordination carry higher operating costs. Done well, these services can improve RevPAR and reduce customer acquisition costs compared to a typical stand-alone STR. For a taste of the experience that drives demand, explore the island’s signature dining at Latitudes on Sunset Key.

Rules and taxes that move your pro forma

Regulation materially shapes ROI in the Keys. Start with what the county requires for any sub-28-day rental activity via the Monroe County Special Vacation Rental Program. Also note that the City of Key West maintains its own registration and overlay constraints that can be stricter in certain neighborhoods. If a Sunset Key parcel falls under city jurisdiction, confirm medallion or registration requirements with the city clerk. You can read a public summary of Key West’s approach here: Key West short-term rental rules overview.

Taxes also matter. Short-term rental income in Florida is generally subject to state sales tax plus local Tourist Development taxes, which owners or managers must register to collect and remit. Be sure to include property taxes, any special district charges and all resort or HOA assessments in your underwriting. A general overview is available here: Florida sales and tourist development tax on rentals.

Physical and insurance risks to quantify

Coastal exposure is a core underwriting variable in the Lower Keys. Regional guidance used by Southeast Florida jurisdictions documents measurable sea-level rise and recommends adaptation planning. On a parcel-by-parcel basis, you will want to know FEMA flood zone designations, finished-floor elevations, seawall conditions and the cost of mitigation such as shutters, generators or elevating critical systems. See regional sea-level context in the Southeast Florida sea-level rise guidance.

Insurance markets across coastal Florida have been volatile in recent years. Premiums and available wind and flood coverage can vary widely by micro-location. Some properties require layered solutions that can affect operating expenses and lender sizing. Begin the quote process early and build scenarios. For market context on Florida insurer dynamics, review this industry risk overview.

Your underwriting checklist

Before final offer, request and review these items:

• Written zoning and use confirmation for the exact parcel, county and city, including whether nightly STRs are allowed or grandfathered. Start with county guidance: Special Vacation Rental Program.
• HOA and association documents that govern rental terms, access rules, reserve studies and any transfer fees. Cross-reference with the operator’s residences overview.
• Operator or management agreement that details commission structure, owner usage, blackouts, and the owner gross-to-net waterfall.
• Owner statements for at least 24 months showing ADR by segment, occupancy by month, and distribution of group business.
• Insurance reports, including FEMA elevation certificates and at least three current quotes for wind and flood coverage.
• A five-year cash-flow sensitivity model with conservative, base and aggressive cases and clear stress tests.

Key KPIs to calculate:

• Break-even occupancy at current ADR after commissions, taxes, insurance, HOA and a conservative capex reserve.
• Net yield to owner (NOI divided by purchase price) under both nightly and monthly rental cases, if legal.
• Loan sizing parameters based on island location, insurance requirements and expected cash reserves.

Five-year model moves that add realism

Anchor your pro forma in the island’s cadence and cost structure:

• Build a month-by-month forecast. Winter months should carry materially higher ADR and occupancy than summer.
• Include full-service management commissions that reflect the actual contract. Model housekeeping and turn costs by bedroom count.
• Set a hurricane and repair reserve that accumulates across years to handle deductibles and quick-turn capex.
• Allocate seasonal marketing spend for shoulder periods and events that match the island’s group-use profile.
• Stress test the base case with +10 to 30 percent insurance expense, +5 percent management fee, and -15 percent winter occupancy.

Working with a team that knows the island

Sunset Key is a niche luxury market with scarce supply, integrated resort services and exacting operating standards. To move confidently, you want representation that blends hospitality fluency with on-island access. The Sunset Key Residences platform, operated under Ocean Sotheby’s International Realty, focuses on exclusive listings and buyer representation for single-family homes and waterfront lots, high-end rentals, and investor acquisition with potential rental conversion. You benefit from boutique, white-glove service, resort integration and global distribution that reaches qualified capital.

If you are ready to evaluate a specific cottage or home, connect with Bob Cardenas and Matthew Carlson for parcel-level guidance, document checklists and introductions to the right on-island resources.

FAQs

What is Sunset Key and how do you access it?

• Sunset Key is a small private island adjacent to Key West with a resort and private residences. Access is by scheduled launch from the sister marina, with services coordinated across reservations, concierge and F&B. See the resort and residences overview.

When is peak season for rentals on Sunset Key?

• The Keys’ high season runs late fall through spring, with peak winter months driving the strongest ADRs and occupancy. Shoulders can perform well, while summer is softer and overlaps hurricane season. See the Florida Keys demand context.

Can you operate nightly short-term rentals in Monroe County?

• Many residential districts prohibit sub-28-day stays unless permitted. Where allowed, you need a Special Vacation Rental permit, a licensed manager and safety inspections. Review county rules here: Monroe County Special Vacation Rental Program.

Do Key West city rules also apply to Sunset Key parcels?

• Key West maintains its own STR controls and registration that can be stricter in some areas. If a parcel falls under city jurisdiction, confirm requirements with the city clerk. See a public Key West STR overview.

What management fees should I expect in a resort program?

• Benchmarks suggest 25 to 40 percent of gross revenue for full on-site resort programs, and about 15 to 30 percent for third-party STR managers, depending on services. See fee norms: vacation rental management fees.

What insurance and climate risks should I model?

• Expect variable wind and flood premiums and consider layered coverage. Quantify flood zone, elevation and mitigation costs, and review regional sea-level guidance. For context, see sea-level rise guidance and a Florida insurance market overview.